Method and apparatus for printing or coating



W. C. HUEBNER METHOD AND APPARATUS FOR PRINTING OR COATING Filed March 17, 1949 Oct. 12, 1954 6 Shets-Sheet l R F- m R ME U E 4 WH 8 M E 5 E W M U w D 7 v Wm m 7 9 7 0/0 3 6/ D. 8 E I I 0 w 2 n 04 a w l1 8 2 Z 7 b. v a M N 8 M 7 vw M r. u T W ID av Q 5 w M ml 0 a M 6 w.

Oct. 12, 1954 w, c, HUEBNER 2,691,343

METHOD AND APPARATUS FOR PRINTING OR COATING Filed March 17, 1949 6 Sheets-Sheet 2 INVENTOR. W1 L LIHM 11H LIEBNER F m "M,

Oct. 12, 1954 w. c. HUEBNER METHOD AND APPARATUS FOR PRINTING OR COATING Filed March 17, 1949 6 Sheets-Sheet 3 INVENTOR. WILLIHM E. HUEBNER I r z HTTHRNE 0 13 m Q: .Q

Oct. 12, 1954 w. c. HUEBNER 2,691,343

METHOD AND APPARATUS FOR PRINTING 0R COATING Filed March 17, 1949 6 Sheets-Sheet 4 INVENTOR. N WILLIHM E. HLIEENER N 1' BY p I 07 HTTURNE s Oct. 12, 1954 w c, U B ER 2,691,343

METHOD AND APPARATUS FOR PRINTING OR COATING Filed March 17, 1949 6 Shae ts-Sheet 5 INVENTOR. WILLiFiM C. HUEENER Oct. 12, 1954 w. c. HUEBNER 2 593 343 METHOD AND APPARATUS FOR PRINTING OR COATING Filed March 17, 1949 6 Shee-csSheet 6 Flqlz INVENTOR. \IVILL x HM EHHUEENEE Bf z lw Zi 2 1?] flW/U.

HTTEIFNEYE f Patented Oct. 12, 1954 METHOD AND APPARATUS FOR PRINTING R COATING William C. Huebner, New York, N. Y., assignor to The Huebner Company, Dayton, Ohio, a corporation of Ohio Application March 17, 1949, Serial No. 81,866

1 54 Claims.

This invention relates to a method and apparatus for printing or coating sheet or Web mate rial, and, more particularly, to a method and apparatus employing an electrostatic field of force to efiect transfer of printing or coating substance or substances to web or sheet material.

An object of the invention is the provision of a universal apparatus capable of utilization for the production of a coating or an image upon sheet or web material by the use of a substance or substances, which are in the form of liquid, semi-liquid, gaseous, suspensions in a liquid or gas, or combinations thereof, the substance or substances being transferred to the sheet or Web material by an electrostatic field of force.

Another object of the invention is the provision of a novel procedure and apparatus for coating or printing upon sheet or web material wherein two substances, at least one of which is in liquid or semi-liquid form, are supplied. to opposite sides of a member at least a portion of which is perforate, one or" the substances exuding through the member to unite with the other substance and the substances after thus uniting being transferred to sheet or Web material to form a coating or an image thereon.

An additional object of the invention is the provision of a novel procedure and apparatus for coating or printing upon sheet or web material as defined in the preceding object and wherein the transfer of the substances, after uniting, on a single surface of the member are transferred to the sheet or Web material by an electrostatic field of force.

A further object of the invention is, the pro vision of a universal apparatus capable of selec tive utilization for effecting printing or coating by the use of products of partial combustion, liquids, suspensions, or the like, or combinations of these substances, by relatively simple adjustments and/or removal and replacing of parts in the apparatus whereby a single apparatus may be readily adapted for effecting a plurality of difierent modes of printing or coating.

[a still further object of the invention is to provide a universal type apparatus for printing or coating sheet or web material wherein gases, liquids, suspensions in either a gas or a liquid, or combinations or" such substances are employed with an electrostatic field of force to effect the printing or coating by: expulsion of such substances through pervious regions of a member cooperating with the sheet or Web material; transfer of th substances from the impervious surface of a member cooperating With the sheet 2 or web material; or by depositing the substances upon sheet or web material interposed between the coating or printing substances and a cooperating member which may be either perforate or imperforate.

A still more specific object of the i -vention is the provision of a universal apparatus for printing or coating web material wherein a rotatable cylinder is provided with a housing about a portion of its periphery, which housing is adapted to enable the use of either gaseous or liquid substances, suspensions in gases or liquids, or combinaticns thereof for efiecting the printing or coating on sheet or web material, the said material either passing about the said cylinder and through said housing or passing in close proxrnity with a portion of said cylinder exteriorly of said housing.

Another more specific object of the invention is the provision of an improved apparatus of the type mentioned in the preceding object and wherein the cylinder has at least a portion of its curved periphery perforate so that print or coating forming substances may be supplied to the sheet or web material from within the said cylinder, transfer being effected by an electrostatic field of force which eiiects movement of the substance or substances through the perforate portions of the cylinder onto the sheet or web material.

Another specific object of the invention is the provision of an improved apparatus of the type mentioned and wherein an imperforate cylinder is employed to efiect the printing or coating, the substance or substances for producing an image or coating being supplied to said cylinder from the exterior thereof and transferred from the cylinder to the material by electrostatic fields of force.

An additional object of the invention i to provide an apparatus of the type mentioned above and wherein novel wiping means are provided to remove surplus image forming substances from the non-image areas of a printing cylinder and to effect better distribution of the said substances in the image areas.

The invention also contemplates the provision of an improved apparatus as defined in the preceding object and wherein the sheet or web material passes around the major portion of the cylinder with the image or coating producing substance or substances introduced into the hoursing on the outer side of said sheet or web material, the said substance or substances being trans ferred to and/or penetrating the material under the influence of an electrostatic field of force.

An additional object of the invention is the provision of a universal apparatus of the type mentioned above and wherein a plurality of separate electrodes are employed within said cylinder and housing and interconnected by an electrical circuit to a power source for supplying electrical energy for effecting precharge of the sheet or web material and of the substances employed as well as producing an electrostatic field of force to transfer and/ or effect penetration of the image forming or coating substances to the sheet or web material, switching means being provided to facilitate ready interchange of the polarities and/or functions of certain of the precharge and transfer electrodes.

The invention further resides in certain novel steps of procedure, features of construction and combination and arrangements of parts of the apparatus, and further objects and advantages thereof will be apparent to those skilled in the art to which it pertains from the following description of the present preferred embodiment described with respect to the accompanying drawings in which similar reference characters represent corresponding parts in the several views and in which:

Fig. 1 is a transverse sectional view through an improved apparatus constructed in accordance with this invention, the frame being omitted and certain portions being shown in elevation for the sake of clarity of illustration;

Fig. 2 is a view similar to Fig. 1 but illustrating the manner in which the apparatus may be adapted for use with web material passing around the image or coating cylinder for effecting printing or coating on the material;

Fig. 3 is a view principally in top plan with portions of the housing broken away and the rotatable wiping means illustrated partly in elevation and partly in longitudinal section through the axis thereof;

Fig. 3a is an enlarged fragmentary sectional View of a portion of the rotatable wiper illustrating the manner in which a permeable wiping surface is provided thereon;

Fig. 4 is a front elevational View, with portions broken away and others shown in section, the view being taken from the left of Fig. 1;

Fig. 5 is a fragmentary sectional View taken substantially on the section line 5--5 of Fig. 1;

Fig. 6 is a sectional view taken substantially on the line 5-5 of Fig. 4;

Fig. '7 is a fragmentary sectional View taken substantially on the line 1-1 of Fig. 6;

Fig. 8 is an elevational view of one of the end plates of the apparatus as seen from the bottom thereof;

Fig. 9 is a fragmentary view of the housing with the cylinder removed and as viewed in a direction looking upwardly within the housing from the normal location of the cylinder;

Fig. 10 is a fragmentary sectional view taken substantially on the line ill-l0 of Fig. 1;

Fig. 11 is a fragmentary view partly in elevation and partly in section illustrating a portion of the image or coating cylinder with the housing and electrodes removed and showing the manner in which the cylinder is supported in the frame together with the passages for supplying printing or coating substances to the interior of the cylinder;

Fig. 12 is an enlarged fragmentary plan view of a portion of the periphery of the image or coating 4 cylinder illustrating the manner in which a perforate or pervious surface is provided thereon;

Fig. 13 is a fragmentary sectional View to a greatly enlarged scale through a portion of the image or coating cylinder illustrating the manner in which spaced imperforate areas CO1'1'vspending to non-image areas are provided on the cylinder;

Fig. 14 is a view similar to Fig. 13 illustrating the manner in which the perforate reas intermediate the imperforate areas may be filled with an insulating material thereby providing an entirely imprevious cylinder to effect one particular group of printing or coating operations; and

Fig. 15 is a simplified, schematic wiring diagram illustrating the manner in which the several electrodes of the apparatus are connected to an electrical power pack or source of electrical energy for providing both precharge potentials and transfer potentials for the various modes in which the apparatus is used, the figure illustrating the switching means employed to select the potentials applied to the various electrodes and the polarities thereof.

In accordance with this invention the novel process and apparatus for printing or coating employ substances which may be gases, liquids, suspensions in gases or liquids, or combinations thereof, the printing or coating substances being transferred to and penetrated into the fibers of sheet or web material by means of an electrostatic field of force extending through. the material. When the lines of the field of force are substantially uniform, a coating or substantially uniform deposit is formed upon the material, whereas if the lines of force are arranged in a pattern in accordance with an image, the substance or substances are transferred to the sheet r web material in a manner which forms an image thereon. It will be understood that in either case, namely coating or image formation, the substance or substances are transferred to and penetrate the sheet or web material without the use of pressure, or substantial pressure, between the material and the member from which the image or coating substances are transferred. This is an important distinction from ordinary printing or coating procedures and apparatus wherein the image or coating is formed on the web material by the exertion of substantial pressure and contact between the image or coating member and the web material. Hence, while the terms printing and coatingv are employed in this application, it is to be understood that in using such terms they are employed in their nearest appropriate terms, since there appears to be no available term in the English language which will accurately define the processes of transferring a coating or image producing substance or substances from a carrying surface to a web material where no pressure is employed to effect the transfer.

Furthermore, throughout the specification and claims, the expression field or force is used similarly as in writings on electrical phenomena to indicate the field or zone within which electro static forces are sufficiently active or powerful enough to effect a transfer of a coating or image forming substance or substances to sheet or web material in the manner indicated herein. Also, the term image and related terms, as used hereinafter, contemplate words, letters, delineations, drawings, pictures, illustrations and the like and the term is intended to embody all such matters or combinations thereof.

For the sake of brevity, the term smoke is hereinafter used to cover gaseous printing, image forming, or coating producing substances and is to be considered as coverin finely divided gaseous suspended particles produced as the result of a partial burning or combustion, whethor this combustion be effected at the time of utilization in the process and apparatus or prior thereto and stored in suitable containers or the like for subsequent use. The term smoke is also to be considered as covering gaseous suspensions of finely divided particles of solid substances and atomized liquids which resemble smoke, or mixtures of such substances with the usual components of smoke.

The term liquid likewise refers to liquid, or semi-liquid, such as or the like, and liquid suspensions or solutions of pigme ts, dyes, powders, metallic dusts and the like. The term liquid is likewise to be understood as covering not only substances which themselves provide an image or coating but also those which assist other substances in forming such images or coatings, such as solvents, adhesives, and the like.

An apparatus constructed in accordance with this invention comprises a coating or image producing cylinder, generally designated 25, which is rotatably supported upon a suitable framework 2!, the said framework also rotatably mounting a second cylinder 22 which provides a web supporting action in certain modes of use of the apparatus. The cylinders 2i and 22 may be adjusted towards and away from each other by any conventional means, not shown, but which are well known in the art. As will hereinafter appear, however, the cylinders and 22 are not in pressure engagement with each other as in conventional printing cylinders but are simply either lightly touching web material therebetween or spaced so that only the image or coating cylinder touches such material.

The cylinder is hollow and has a perforate surface, the cylinder, being, for example constructed substan ially as shown and described in my Patent No. 2,6l5,38 entitled Universal Printing Process Cylinder and Method of Making the Same. For the purposes of this disclosure it is sumcient to note that the cylinder 2?; may comprise a cylindrical shell which is provided with a plurality of openings or ports of relatively small diameter spaced points about its periphery, these openings being interconnected on the outer surface of the shell by longitudinally extending grooves such as 25, see Figs. 11 through 14. The ends of this shell are removably supported upon end plates or ineinbers and see l, 5 and 11. Between the shell the members 23, 2? are provided suitable insulat' 1g members 28 so that the shell 23 is insulated from the end plates. The end plates and 2? are rotatably mounted upon non-rotatable tubular members 38 and by means of anti friction bearings such as 32, the shafts and Si being supported in the frame 2 I.

The insulating member 25 preferably has an integral disk-shaped portion providing a seal for the adjacent end of the shell 23 and this member has a centrally located bore or opening 34 which extends coaxially and is in communioaticn with the bore 35 extending through the tubular member 39. lhe adjacent faces of the end plate 26 and the member 28 are counterbored and provided with packing means which,

in the illustrated embodiment, comprise suitable packing material 38 received in the member 28 and a packing nut or gland ti supported in the tubular member 33. The member 26 is provided on its inner face with an annular groove 38 coaxial with the bore 3 and within this groove is received a cylindrical boss 39 provided upon an insulating member or disk the diameter of which is less than the internal diameter of the shell lhe adjacent faces of the members 23 and 4e are spaced from each other and the boss or cylindrical portion 39 has a plurality of circumferentially spaced openings therethrough, thereby providing a communication between the bore 34 and the space between the two members 28 and t2 exteriorly of the boss 33.

The insulating member 29 at the other end of the cylinder is provided with a reduced diameter inwardly directed extension $2 on which is supported an imperiorate cylindrical shell 43, the other end of the shell 43 being supported upon a reduced o a eter portion of the insulating member or disl: so, see Figs. l 11. There is thus provided a space intermediate the shells 23 and which communicates with the previously-mentioned space between the members 28 and it and hence with the bore 35. Suitable seali g means 55 and all are provided intermediate either end of the cylindrical shells 23 and the cooperating end members therefor to prevent leakage of fluids therebetween. Consequently, fluids such as gases or liquids may be introduced from t-e exter' of the apparatus through a connection applied t the threaded outer end of the stationary tubular member 39. The said fluid thus supp ied passes through the bore and the openings all to the annular chamber and thence flows outwardly through the perforations such as and groove 25 and is distributed over the outer surface of shell 23 by the grooves 25.

Bisposed upon and forming a covering for the outer surface of shell is a helically wound, ribbon-like member or strip 4'? which has its ends secured to the imperforate end portions of the shell 23 by soldering, welding, or the like to pin members such as As shown in Fig. 12, the ribbon or strip member 47, which may be formed from wire, preferably has one side substantially planar the other side provided with spaced protuberances or aosses such as so that when the strip is wound upon the drum, the protuberances of one convolution abut the planar face of the next convolution, the protuberances bein so spaced with respect to the circumference of the that the resulting spaces between adjacent protuberances are preferably in stag ered relationship in adlacent convolutions. The strip-like member ll is wound over substantially entire surface of the shell 23 in this manner, thus providing a plurality of capillary type openings 5%] which communicate with the grooves 25 and the openings 2 to permit exuding or flowing of fluid from the interior of the cylinder to the outer surface of the wire or strip ll. The width of the strip-like member an of the openings formed between the protuberances, are so small and numerous that fluid flowing or exuding outwardly froi... the several elongated opensuch as it therethrough can merge on the outer surface providing a substantially continuous film thereover. When the fluid is a liquid the exuding or flow is such that the resulting film upon the cylinder does not readily drip or flow therefrom. By way of example, a strip or wire member 4'! having a height of about .616", a thickness of approximately .005" and protuberances of about .0015 has proved satisfactory in practice. However, strip-like members of any suitable dimension may be used, depending upon the type of fluid used within the cylinder. It will be evident that the outer surfaces of the convolutions of the wire or strip t? are initially not flat but will be rounded somewhat, which facilitates use of the cylinder when a coating is to be formed upon web material, since it facilitates union of the separate portions or drops of the coating producing substance exuding through the openings 5i}.

When the cylinder is to be used for image production, selected areas of the wire or strip M, representative of the non-image portions in the image to be produced are covered by an imperforate material such as a copper shell. This may be effected as is fully described in my abovementioned Patent No. 2,615,389 or by other suitable means which do not per se form a part of this invention, and hence need not be here described in detail. For the present purpose, it is sufficient to note that a thin metallic shell Si is formed in the non-image areas of the cylinder with the image areas left open, as indicated at 552, in Fig. 13, so that fluid supplied to the interior of the cylinder may now move outwardly only through the image areas 52.

As hereinafter described, a cylinder such as mentioned above may also be utilized as an inn perforate cylinder for printing or coating in ac cordance with the procedures disclosed in my copending application Ser. No. 74,822 filed Feb ruary 5, i949, and entitled Combustion Precipitronic Process and Apparatus. In such a process the entire surface of the strip member ll is covered and no fluid is emitted from the interior thereof. When a coating is to be formed the entire surface of the strip or wire il is preferably provided with a conductive shell such as copper or the like. When an image formation is desired, the image areas of the cylinder are provided with conductive portions such as the previously mentioned portions iii, and the previously mentioned spaces 52 are now filled with an electrically insulating material d3 of suitable type, the entire cylinder then being subjected to a light surface grinding to render the surface smooth.

A cylinder of the type described may also be employed to effect the formation of an image or a coating by supplying the image or coating producing material to the outer surface of the cylinder. For utilization in this manner, the entire outer surface of the strip or wire member ti is covered with a metallic covering or shell. W hen a coating is to be produced the said metaliic covering or shell pref rably has the entire surface lightly etched in a network of lines to assist in proper distribution of the coating substance over the surface of the cylinder and retention thereon until transfer is effected. When an image is to be produced, the image areas may be formed by forming recesses in the covering shell in the image areas thereof as by etching or depressing the shell in such areas.

The hollow tubular support 3| for the lefthand side of the cylinder 29, as viewed in Figs. 3 and i, has a tube of insulating material 54 extending therethrough, the inner end of this tube being received in a recess provided in the insulating end member as, see Fig. 11. The insulating tube Ed is therefore stationary and provides a support for electrode means within the cylinder 20 which electrode means include both electrodes for effecting transfer of printing or coating substances and electrodes for precharging such substances. As hereinafter described, certain of these electrodes are utilized for one function in one type of operation and for a different function in a different type operation.

As is shown in Fig. 1, the insulating tube or member b t has a transfer electrode 55 supported thereon. and extending radially therefrom and towards the cylinder 22. This electrode 55, which is preferably of the blade type, extends longitudinally within the cylinder 26 and has an electrical connection with an insulated conductor 53. The latter extends through the interior of the member 54 to a position exteriorly of the apparatus and is connected in a suitable circuit, as shown in Fig. 15, for supplying electrical energy to the electrode. Also supported upon the insulated member 5d are arcuately shaped electrode members 5? and 58 which are connected together by semi circular conductive portions such as 59,

the latter in turn being connected by a wire 68 to the previously mentioned electrical circuit. The electrode members 5? and 58 each comprise a plurality of longitudinally extending blade-like projections bl extending radially in spaced relationship from integral segmental portions such as 62 which are either connected to, or formed integral with, the previously mentioned semi-circular portions 59.

Also disposed within the cylinder 28 is a resilient contact member 63 which has a sliding contact upon the inner surface of the inner shell 13, the contact being stationarily supported upon a radially extending arm 6t which is mounted upon the member 5 the arm 64 being electrically connected to an insulated conductor 55 which is also connected in the previously mentioned electrical circuit illustrated in Fig. 15.

The lower cylinder 22 is preferably formed similar to that described in Patent No. 2,408,144 issued to William C. I-luebner on September 24, 1946. For the purpose of this disclosure it is sufiicient to note that this cylinder comprises a shell tit, see 1, which is formed of conductive material and is insulated from the endplates and bearings for the cylinder. Disposed within the cylinder 22 is an insulating tubular member 61 upon which is mounted a transfer electrode 68. This electrode is preferably plate-like in form and extends longitudinally of the cylinder, the electrode being electrically connected to an insulated conductor 69 which extends through the member 6? to the exterior of the apparatus and is connected in the previously-mentioned electrical circuit as shown in Fig. 15. Also supported upon the insulating tube or sleeve 8'? is a magnevic shielding means for confining the electrostatic field of force existing between the electrodes 55 and E56 when the latter are supplied with electrical energy. This magnetic shielding means comprises a plurality of electromagnets it, ll mounted adjacent the ends of U-shaped armature members it, the ends of the U-shaped members being provided with suitable pole pieces "l3 and it. The U-shaped members '52 and hence the electromagnets and pole pieces are all supported upon the insulating sleeve or tube 6'! by means of insulating brackets which are carried by the sleeve member 61; see the previously mentioned Patent 2,408,144. Also, as described in this patent, the electromagnetic shielding means may be adjusted towards and away from the shell 68 by means of adjusting screws 76 to thereby regulate the action of the magnetic fields produced thereby upon the electrostatic field, it being understood, however, that in no case are the pole pieces brought into contact with the interior surface of the shell 36. The cylinder 22 is adapted to be rotated in timed relationship with cylinder 2|, when the parts are in the positions shown in Fig. 1, by means similar to that disclosed in Patent No. 2,408,144.

Supported upon the framework 2i, and adapted to surround a portion of the periphery of the cylinder 2i is a housing generally designated Tl. This housing is preferably formed in two arcuate portions each comprising outer arcuate walls l8, l9, respectively, and inner arcuate walls 86 and 3|, respectively. The inner and outer walls have a curvature such as to be substantially coaxial with the cylinder 26 and extend in spaced relationship longitudinally thereof. The adjacent edges of the outer walls 78, 19 of the two arouate portions have integral upturned flanges which are respectively secured to longitudinally extending, vertically disposed, elongated members or plates 82 and 83. Likewise, the inner walls 823 and 8! of the housing have their adjacent edges provided with integral upturned flanges also secured to the elongated plate members 82, 83. The ends of the housing 11 are provided by end plate members 84 and 85, see Figs. 1 to 6 and S, which are formed of insulating material and are provided with arouate grooves such as 85, 87, SS and 89 in which the ends of the arcuate walls 78, i9, 88 and SI are adapted to be inserted. This arrangement of parts likewise closes the ends of the space between the vertical members or plates 82, 83, the width of that space being determined by the spacing of the arcuate grooves 8b to 8d.

The lower ends of the walls 78, I9, 8 3 and 3! are each provided with integral flange portions. These lower flange portions of the walls i8, 88 are secured to a longitudinally extending, horizontally disposed member es. Likewise, the lower ends of the walls l9, 8! are secured to a longitudinally extending, horizontally disposed member 9!. The members 90 and 9! are also secured to the end walls 24, 85, thereby retaining the parts in their aforementioned relationships and providing a unitary housing which is supported from the framework 2| by suitable posts and cooperating screws 92 and 573, respectively; see Figs. 4 and 5.

The upper edges of the vertically extending members 82 and 83 are provided with a cap or top closure 94 which extends over the tops of these members and is suitably secured thereto, thus defining a closed space or well between the members and extending longitudinally of the cylinder 243, this space or well being adapted to supply a liquid to the exterior surface of the cylinder. For this purpose one of the members 82, S3, in this case the member 83, is provided with an opening in which is secured a conduit 35 for conducting a liquid into the said space. In order to regulate the quantity of liquid supplied to the cylinder, the lower edges of the members 82, 83 are provided with adjustable sealing means adapted to be selectively placed in engagement with the surface of the cylinder 29 or to be spaced therefrom any desired amount to thereby regulate the application of liquid to the cylinder 2B. These sealing means are identical and 1% therefore a description of one both.

As shown in Fig. 10, the sealing means comprises a strip of leather or composition material which is adapted to extend longitudinally of the cylinder 26, the upper edge thereof being secured in a substantially U-shaped support member ill. The support member is provided on its upper surface with a plurality of integral threaded bosses 98 adapted to receive the threadlower ends of screws 39. The members 95 are fitted into longitudinally extending grooves lower end of the vertically extending members t2 and 83 with the screws 99 extending upwardly through suitable openings therein and having their heads disposed above the member or cap 9 5. Intermediate the upper surface of each support member *3? and the upper portion of the groove, such as me, in which the sealing means are provided, is inserted a suitable resilient means which, in the present form, is illustrated as a fiat curved spring l 0i bearing upon both the member 83 and the member ill for exerting force in a direction tending to effect engagement of the strip 95 with the surface of the cylinder 26.

Ordinarily, the heads of the scrum-s L spaced slightly above the plate or cap member 94 so that the sealing strips remain in engagement with the surface of the cylinder under the action of the springs lei, thereby suring a good contact with automatic COll sation for wear of the strips being effe the action of the spring leli. If it be desir retract the lower edges of the strip meinbe"-- from contact with the cylinder as for ple, when it is desired to apply a to the cylinder 2%] for the purpose r the like, or when web material is wound about the cylinder 20 as hereinafter described, t'e screws 99 are threaded inwardly into the bosses 98 whereupon the heads of the screws enge the cap member 24 compressing the spring n ber I81 and withdrawing the members engagement with the cylinder 26. The limit of this withdrawing action is substantially that indicated in Fig. 2 from which it will be seen that the members can be withdrawn to a position such that their lower edges are substantially aligned with the lower edges of the members 33, the limit being determined by engagement of the upper faces of the bosses with the upper surface of the grooves 59.

The members til, iii are each provided ih sealing means, generally designated $92 which sealing means are constructed in th same manner and operate upon the same principles as the members to till which have just been described. These sealing means are adapted to cooperate with the surface of the cylinder 25 when the screws 99 are in their positions indicated in Fig. 1 thereby providing a substanti lly fluid tight seal for the spaces or compar tnent between the walls 8i, and the cylinder The sealing strips 35 of the sealing means it I93 may, however, be withdrawn f engagement with the cylinder 23 in the nanner previously described to permit passage of web inaterial about the cylinder 28, the position of the parts at this time being indicated in Fig. 2.

Sealing is also provided between the areuate portions of the inner edges of the end plates or members 85, t5 and the cylinder adjacent the outer ends of the latter. This sealing in the form of arcuately shaped strips it formed from leather or suitable composition,

is a description of which are respectively supported in recesses provided in the inner edges of the plates 84, and 85. The sealing strips or members d, [85 have their inner arcuate surfaces extending into engagernent with the cylinder 28 and these said inher arcuate faces are provided with a plurality of spaced circumferentially extending grooves such as Hi6. In the illustrated form, each of the strips ifi l, N35 has two such spaced grooves act, thereby providing three spaced lands in engagement with the cylinder 29. These sealing means Hi4- and tilt prevent any flow of fiuids from the housing ll longitudinally of the cylinder ea.

In order to supply a fluid in the nature of smoke or smoke mixed with vaporized liquids to the apparatus, a plurality of conduits it? are connected to the outer shell "it of the housing, the interiors of the conduits communicating with the space or compartment Hi8 intermediate the shells it, at. The several ducts it? are preferably connected to a common longitudinally extending conduit lll'la. The inner shell 8!), which forms one wall of this compartment W8 is provided with a plurality of spaced openings its, see Figs. 1, 2, 3 and 9, so that communication is provided between the space or compartment Hi8 and the space or compartment ilii intermediate the shell 85 and the surface of the cylinder Zil. The longitudinally extending member 95 at the lower edges of the shells l3, 89 is provided with interconnected openings or ducts i l i, i it, the latter extending substantially horizontally through member ill) from the exterior of the housing to a point adjacent the periphery of the cylinder 2% while the duct or opening l l i communicates with the duct l l2 and with the compartment or space lit. The outer end of the conduit or duct H2 is preferably closed by an end plate H3 suitably secured in place, the duct or passage H2 being in communication with a suitable conduit or conduits li i which lead to a means for creating a partial pressure or vacuum, not shown. Preferably, ther are a plurality of conduits Hi l extending substantially vertically at spaced points from the member st and united with a single horizontally extending duct or conduit l 55 for communication with the aforementioned means to produce a partial pressure or vacuum. It will be apparent from the construction described that smoke or gaseous suspensions introduced through the conduits Hlla and lill' will circulate through the space or compartment ltd, th nce through the openings Hi8 into the compartment i iii and through the latter adjacent the cylinder iii to and through the openings i l E and M2 to the exhaust conduit H5 under influence of the partial vacuum in the latter. The end of the opening or duct H2, adjacent the cylinder ii, prevents escap of smoke or the like from between the cylinder and the housing at this point.

The construction just described is repeated for the portion of the housing represented by the shells it, til and member 9!. That is to say, a plurality of conduits or ducts H6 communicate with a space or compartment ill intermediate shells i9, 8! and the inner shell ill has openings lid providing communication between the space or compartment l l? and a space or compartment H9 between the shell 8i and the cylinder 28. Likewise, the member 9! is provided with a substantially horizontally extending opening or duct 52! the outer end of which is closed by a plate 32!, the duct being connected to a plurality of vertically extending pipes or conduits 122, and the inner end of the opening or passage 52% communicating with the compartment or space lit through a laterally extending opening lit in the member 9i. Likewise,- the pipes or conduits 122 are connected to a horizontally extending conduit 22% similar to the conduit H5 and these two pipes or conduits llii, $24; are preferably united together for convenience in applying the partial pressure or vacuum thereto. Smoke, vapor or the like introduced through conduits i it will circulate through the space or compartments iii, openings lit, and space or compartment M5 to and through the exhaust open ings i2 3 and 23 to the conduit 62 5 under the influence of the partial vacuum in the latter. The end of the opening i238 adjacent the cylinder it prevents the escape of smoke or vapor at this point.

Disposed within the compartments I I0 and lit for cooperation with the periphery of the cylinder 20 are a plurality of wiping means, In the present embodiment, the wiping means are shown as being removable and comprise spaced longitudinally extending strips of felt, or the like, I25 which are removably supported in substantially U-shaped clips i226 secured to the shells N and 8 l. The clips E28 may, if desired, be made somewhat resilient to facilitate the insertion and removal of the wiping material I25 and to properly retain the latter in position therein. Any appropriate or desired number of wipers may be utilized but the illustrated number and position of wipers has been found advantageous. As will be seen in Fig. 9, the wipers 525 preferably are slightly shorter than the distance between the end plates 85,

of the housing and adjacent ends of the wipers are staggered as shown in Fig. 9 to facilitate circulation of smoke or vapor in certain modes of utilization of the apparatus as will hereinafter appear.

In addition to the wiping means within cornpartrnents i it and i It, a rotatable wiping means, generally designated lZ'i, is rotatably supported on the frame 2! exteriorly or" the housing 'i'l and adjacent the member ill. The rotatable sup port for the wiping means l2l is preferably so constructed that the axis of the wiping means may be moved towards and away from the axis of the cylinder 28 to thereby selectively effect contact of the wiping means with the cylinder 25 or to disengage these members. For this purpose the frame 2! is provided with a pair of brackets I28, see Figs. 3 and 6, adjacent opposite ends of the cylinder, the adjacent faces of the brackets being provided with rectangularly milled openings in which are slidably mounted rectangular bearing blocks 529 in which the cylindrical ends of a conduit member ltd are non-rotatably supported. The blocks E29 are each provided with a pair of parallel extending openings through which pass screws ltl and W2, the inner ends of the screws being threadably received in threaded openings of the brackets lZS. The screws 53! and i312 are provided with flange portions or collars l33 on either side of the bearing blocks iztso that rotation of the screws effects movement of the hearing blocks within the brackets, thereby shifting the shaft I36 with respect to the frame 25 and hence relative to the cylinder 29. Also, by completely removing the screws iti, itQ from the brackets $28, the bearing blocks I29 and hence the entire rotatable wiping means i2". may be readily removed from the apparatus.

The wiping means i2? comprises a perforate shell E34 having inwardly directed flanges i353 at the ends thereof which are journalled upon the cylindrical portions of the conduit member I39 by antifriction bearings I36. Disposed upon the outer surface of the perforate member I 34 is a permeable wiping surface which, in the present embodiment, is shown as constructed of a plurality of annular washers I37 formed of felt or other suitable material, see Fig. 3a. Interposed between adjacent felt washers I37 are washers or disks I38 which are preferably formed of metal and have a lesser outside diameter than the felt washers I37. Preferably, the side surfaces of the washers or disks I38 are provided with outwardly extending projections or protuberances which embed in the sides of the felt washers I 37. The disks or washers E38 are keyed to the perforate member I34, by integral lugs or key portions I38a on the former engaging in a keyway I 34a on the latter, and the washers i3? and I38 are held in side engagement by suitable means, not shown, so that the felt washers are caused to rotate as a unit with the perforate cylinder I34. The cylinder I34 is rotated by suitable means such as a belt I39 which is connected from a source of power, not shown, and extends around a pulley I49 provided on or formed integrally in the portion I35 of the cylinder I34.

The conduit member I has a radial portion I41 extending longitudinally intermediate the end portions I of the perforate member or cylinder I34. The outer edge of the portion 54! extends closely adjacent the inner surface of the shell I34 and is arcuately curved concentric therewith. The outer arcuate face of the portion I 4! has a longitudinally extending groove or recess i 12 therein adapted to successively communicate with the perforations in the shell I34 as the latter rotates therepast. The groove I42 communicates with a plurality of radially extending openings or passages I43 vhich in turn communicate at their lower ends with a central opening or chamber [44 in the member I 30. The opening or chamber I44 may be formed by a milling or other suitable operation, the lower side of the completed chainber being closed by a plate I3ila. The central opening or chamber has an axial extension formed by a bore I44a extending to one of the ends of the member I30. The outer end of this bore MM is threaded and hence is adapted to be connected with a pipe or conduit, not shown, communicating with a source of fluid pressure such as compressed air.

It should now be apparent that, when the rotatable wiping means I27 has been adjusted into operative engagement with the cylinder is, and is rotated in the opposite direction to the rotation of cylinder 20, the liquid wiped by the former from the latter, and normally absorbed into the felt, is removed therefrom by the air or other fluid under pressure issuing from the opening or groove I42 as the portions of the wiper pass thereover. To withdraw this removed liquid and prevent it from being deposited upon other portions of the apparatus, the rotatable means I27 is substantially enclosed by a housing or shield I45 con municating with a region of reduced fluid pressure, such as a chimney or a chamber provided with an air exhaust fan. This shield may be made in several parts and is shown as comprising substantially cup-shaped end portions I46 and I47 connected with the aforementioned bearing blocks I29. The cup portions I46, I47 are connected with arcuate portions I48, I49 extending longitudinally of the wiper and removably secured to the cup portions. The longitudinally extending arcuate portion I 49 has its upper edge pro- Vided with an outwardly extending flange por" tion which is connected with a plate I53. A secend plate I5I is supported in spaced relationship with the plate I58 and has an outwardly extending flange of an arcuate shield portion I52 connected thereto. The shield portion i52 is, like the portions I 48 and M9, removably secured to the members i 33, sufficient space ing provided intermediate the edges of the arcuate portions I48 and IE2 to permit cooperation of the wiping means with the cylinder 26. The space between the plates IE8 and i5! is closed at the outer end by a member I53 and the sides of this opening are likewise sealed, thereby providing a duct or passageway which is connected with upstanding ducts or conduits I54, the latter in turn being connected to the previously mentioned conduit I23 which, it will be remembered, is in communication with a region of reduced fluid pressure. The connections between each conduit I54 and the conduit 24 preferably includes a flexible portion I55 to permit movement of the wiper mechanism I27 its shield rela tive to the housing 77 and the conduit 24, Figs. 1 and 2 showing respectively the two extreme positions of the wiping mechanism 527 while the latter remains mounted in the machine. inter mediate the pulley I40 and the felt washers i l, the shell or cylinder I34 is provided with a clrcumferentially extending groove in which a sealing washer 135a is mounted for cooperation with the shield I to prevent fluid leakage at this point. The directions of rotation of the wiping means I27 and of the cylinder 2d are indicated arrows in Fig. 1 from which it will be observed that these two elements are rotated in opposite directions.

It will be apparent from the construction just described that, when the wiping mechanism 52? is in engagement with the cylinder 2?, liquid. removed by the wiping mechanism from cylinder and this liquid is in turn removed cm the felt washers l3! by the fluid pressure teed from the groove or opening I42 as successive portions of the washers I3? pass thereover. The liquid thus displaced by the fluid pressure, being in the form of a vapor or spray, is readily withdrawn through the conduits 5554, E and 524 due to the partial vacuum or reduced pressure main-- tained therein. When the rotary wiper I 27 is moved out of operative relationship with the cylinder 29 to a position such as indicated in Fig. 2, it need no longer be rotated and the fluid pressure supplied thereto is terminated. The partial vacuum applied through the conduits see, a may be also terminated, if desired, or may be left in operative relationship.

Web material may be introduced into the apparatus and into cooperative relationship with the cylinder 26 in either of two ways in accor ance with the type of coating or printing to be effected thereon. As shown in Fig. l, the web material M comes from a source of supply, not shown, and is led around an idler or directionchanging cylinder I56 which is suitably supported in the frame 2i adjacent the cylinder 22 and spaced therefrom sufnciently to permit passage of the material M. The web material after passing about a portion of the cylinder I55, then passes around a portion of the cylinder 22 and between the latter and the cylinder 2d, the material continuing therefrom to a suitable takeup mechanism not shown. The cylinder 22 forms a support for the material to maintain the latter closethe ly adjacent the cylinder 20, but no pressure is exerted between these latter two cylinders since the coating or printing upon the material M is eifected by transfer of the printing or coating substances from the cylinder in by an electrostatic field of force as contrasted with pressure as in conventional procedures.

In order to provide an electrical precharge upon the web material M before the latter passes adjacent the cylinder iii and through the electrostatic field of force utilized for transfer of the coating or printing substance, the said material passes adjacent an electrode means generally designated lt'l. This electrode means comprises a plurality of spaced rods or wires its which ex tend longitudinally between the end plates t l, 85 and are supported in the latter, the rods or wires tilt being disposed in a somewhat arcuate configuration concentric with of the cylinder 22 when the latter is in its position shown in Fig. 1. The outer ends of the electrode wires or rods i553 extend beyond the outer faces of the end plates 35*, 8E and are electrically connected together by soldering, welding, or the like to a conductive strip E59, see Fig. a.

Web material may also be introduced into cooperative relationship with the cylinder iii in the manner shown in Fig. 2 from which it will be observed that the material such as M, coming from a source of supply not shown, passes around idler rollers or cylinders its and E55 which are supported upon the frame and extend through suitable cutout portions of the end plate members 8t, 85 of the housing. The web material M, after passing around the rollers or cylinders its, 5511, then passes through the housing l'i by being wrapped around the periphery of the cylinder 2G and is led therefrom tangentially between the cylinder 26 and the cylinder 22. When the material is fed in this manner, the rotatable wiping means i2? and the cylinder 22 are normally moved to positions where they are spaced from the cylinder 2b, as indicated in Fig. 2, and the stationary wipers such as 25 are removed from the housing, while the sealing means carried by the members 82, 83 and 9t, 95 are retracted from engagement with the cylinder by operation of the screws 99-, the position of these parts in their retracted position likewise being illustrated in Fig. 2.

In order to provide a precharge for the web material M before the latter is conducted about the cylinder 2t, an electrode means it? is provided intermediate the rollers ltd, iti. This electrode means is constructed similar to that designated l5? and likewise comprises a plurality of longitudinally extending rods or wires 563, the ends of which are supported in the end plates 8d, 85, the rods or wires ltd being disposed in a plane adjacent the path of the material between the rollers Hit, lfil. The ends of th wires or rods H63 which extend beyond the sides of the end plates 36, are electrically connected together as by welding or the like to connecting strips Hi l.

In addition to the electrode means just described, electrode means are also provided to supply an electrical precharge to smoke or other fluid entering the apparatus through the conduits it? and i it and circulating through the compartments I98, l iii and i Hi3 respectively. For this purpose an electrically conductive rod or wire ltd extends through the space or compartment His intermediate the walls it, all, the ends of this rod being supported in the end walls 84,

with at least one end of the rod extending sufiiciently beyond the end wall for connection of an electrical conductor thereto; see, for example, Fig. 5. A similar electrically conductive rod or wire M55 is provided in the compartment il'i extending therethrough between the end plates 8Q, 85 for recharging smoke or other fluids passing through the compartment i it prior to its introduction adjacent the surface of the cylinder ill.

Electrode means are also provided in the cornpartments or spaces ilil and H9. lhese electrode means likewise comprise a plurality of electrically conductive rods or wires extending longitudinally of the housing and secured at their ends in the end plates or walls t l, 85. Thus, the electrode means in the compartment lib, designated Mil, comprises spaced rods or wires E88, the outer ends of which extend through the end wall of the housing and are electrically connected together by a conductive strip 359, see Fig. 5. Likewise, the electrode means in the compartment Hi3, generally designated iii comprise spaced rods or wires ill electrically connected together by a common connecting strip. The wires I53 and I?! are disposed in arcuate configurations about the surface of the cylinder 20 and spaced therefrom and these wires, being oppcsite the blade edges of the electrodes 5?, 58, may be used for either precharging substances on the surface of the cylinder 28 when the electrodes 68 are used for transfer of the substances, or may themselves be used for effecting the transfer of substances when the web material such as M is wrapped around the cylinder '33 as indicated in Fig. 2.

In addition to the features of construction just mentioned, an arcuate shield ila extends longitudinally of the housing ll adjacent the surface of the cylinder 29 intermediate the cylinder 22 and the roller llil. This arcuate shield or plate lid is secured to the end plates ea, 85 by angular portions or brackets lib which are held by means of screws or they may be otherwise connected to the end plates. As will be observed from Fig. 2, this shield lla substantially closes the portion of the surface of the cylinder 2E3 which is not covered by the web material M when the latter is con ducted about the cylinder iii as shown in Fig. 2. Consequently, when the is used in the manner indicated in Fig. 2, and as hereinafter more fully described, smoke or other fluid admitted to the interior of the cylinder it cannot freely flow from openings in the cylinder at the portion intermediate the rollers iiii and cylinder 22 and which is not covered by the web material M.

Fig. 15 illustrates a simplified form of electrical circuit for interconnecting the previously mentioned electrodes. As shown therein, power lines Li and L2 conduct electrical current from a con mercial source of supply to a conventional power pack or supply unit H2. This unit is adapted to provide direct current of two diiferent potential differences, the potential difference provided at the output wires 6'53 and lid being, for example, in the order of twice that between the output wires We and lit. The higher voltage or potential difference at the wires H3, FM is employed for the transfer electrodes to establish the electrostatic field of force therebetween which effects transfer of substances to the web material, while the lower voltage or potential difference between the wires H5 and H6 is connected with the precharge electrodes to supply the web material and the printing or coating substances with electrical charges prior to their being subjected to the electrostatic field of force. The power supply unit or pack I i2 is preferably pIOVidBd with adjusting means operated by knobs, such as Ill and I18, to control the voltages applied to the leads I73, I14 and I15, I I6, respectively. The power pack or unit I I2 is also preferably provided with indicating meters I19 and I80 to indicate the potential difierences or voltages supplied to the two sets of output leads. Since the power supply unit I12 is of conventional construction, the details thereof need not be described.

The output lead I13 is connectible through a reversing switch I8I to the previously mentioned wire 55 which, as previously mentioned, is connected with the transfer electrode 55, this connection being efiected when a movable blade I82 of a multipole, double-position switch, generally designated I'83, is positioned as indicated in full lines in Fig. 15. The wire I14 is connectible through a second portion of the reversing switch I8I to a wire I85 which is in turn connected through the movable blade I86 of the switch I83, when in its full line position of Fig. 15, to the previously mentioned wire 69 connected to the transfer electrode 68. In addition, the switch I83, when in the position indicated in full lines in Fig. 15, has the output terminal [25 of the precharge voltage connected through a reversing switch I81 to a wire I88 which is in turn connected by the movable blade I89 of the switch I83 to the wire I90, the latter being connected by a wire I 9I to the precharge electrode I'IEl located within the chamber H9. The output wire I76 of the precharge voltage is at the same time connected through the reversing switch I87 to a wire I92 and thence through the movable blade I333 of the switch I83 a wire I94 which is in turn connected to the precharge electrode It? for the web material M. The polarities of the potential differences or voltages applied to the electrodes 55 and 68 and to the electrodes I? and Ill? may be reversed simultaneously by simultaneous operation of the switches I3! and Iiil, these switches being preferably ganged together for common actuation, as indicated in the drawing. Consequently, the polarity of the charge supplied to the web material is kept the same at all times as that applied to the electrode 68 and the polarity of the potential applied to the electrode I'Iil is the same as that applied to the transfer electrode the polarities being reversed as indicated when the coating or printing substance is such that it mor readily receives a charge of one type than of the other.

With the switch I83 in its broken line position indicated in Fig. 15, the wire I73 is now connected through blade 382 to a wire L 35 which is in turn connected through a reversing switch I96 to a wire I97, the latter being connected to the wire ISI and hence to the electrode I Iii. The wire It? is also connected by a wire I98 with a movable blade ills of the switch I83 which now closes a circuit to the wire 2% connected with the electrode means it? within the compartment III! of the housing. The movable blade 586 of the switch has now closed a circuit to a wire I which is in turn connected through the reversing switch see to the wire fill for the electrode means 57, located within the cylinder 29. The switch. blade I23, of switch I83, in the broken line position of Fig. 15, closes a circuit to a wire 282 and through a switch blade 233 and a wire 294 to the precharge electrode I62 for the web material M. The switch blade I39 of the switch I83 would then close a circuit to a switch blade 2% and from the latter this circuit extends through a wire 2% and a switch blade 299 to the electrodes I and IE6 in the compartments I538 and Ill, respectively. The switch blades 2G3 and 205 are connected for common actuation along with the reversing switch 96 and, hence, when the switch I96 has been moved to reverse the previously described connections extending therethrough, the switch blades 2G3 and 235 are then moved to their broken line positions illustrated in Fig. 15. In those positions, the switch blade 203 closes a circuit between the wire 29 i and a wire 25? connected with the wire I 88 and the blade 2B5 completes a circuit from the wire 206 to a wire 265 and thence to the wire I92. The previously mentioned switch having the movable blade 2639 is adapted to connect the wire 2% to the electrodes 55, I68, as before mentioned. however, when the switch blade 269 is thrown to its broken line position shown in Fig. 15, a circuit is completed from the wire 2% to the wire 65 and hence to the contact 53 riding in engagement with the interior of shell 63 of the cylinder 28. The manner in which the circuit lustrated in Fig. 15 is employed to perform the various operations of coating or printing upon web material will be more fully apparent in the hereinafter described operation of the machine, in conjunction with the present preferred modes of utilizing the latter.

OPERATION The apparatus illustrated and described may be employed for forming an image upon web material by means of a liquid printing or coating substance supplied directly to the exterior surface of the cylinder 29. When employed in this manner the apparatus is in substantially the condition illustrated in Fig. 1, wherein it will be observed that the web material M is fed over the idler cylinder or roller I56, thence about a portion of the cylinder 22 and between the latter and the cylinder 25' The stationary wiping means I25 and the rotatable wiping means I2? are in position, as indicated, and the cylinder 29 employed has the surface thereof provided with recesses or depressed areas in the image portions. These recesses or depressed areas may be pro vided, for example, by employing a cylinder 2-; such as illustrated in Fig. 13 wherein it will be observed that the copper shell or covering 5I occurs only in the non-image areas and the image areas therebetween are in the form of pockets or recesses or the cylinder may have a complete shell over the strip or wire member ti with the image areas provided by depressions or recesses in this shell as by etching or the like. The substance to be employed for forming the image, being in liquid or semi-liquid form, is supplied through the pipe or conduit into the space between the elongated members $32, 33 so that it is applied to the exterior surface of the cylinder 25, excessive flow from the source of supply onto the cylinder being prevented by the previously mentioned members 95 carried by the members 32 and 83.

At this time the electrical circuit will be con ditioned as shown in Fig. 15 so that the switch I83 has the blades thereof in their full line positions as are also the switch blades 293, 2:35 and 289, the reversing switches l8i, l3? having been thrown to a position so that the polarities supplied to the various electrodes are in accordance with the electrical characteristics of the material employed. Therefore, the transfer potential difference between the wires I13 and I'M is supplied to the electrodes 55 and 68 through the switch blades I32 and I86 respectively, while precharge potentials are applied to the electrodes I57 for the web material and I18 for the liquid, these connections being effected through the switch blades I93 and I89.

The liquid, as supplied to the exterior surface of the cylinder 28, fills the depressed or recessed image portions or areas thereon, the liquid upon the non-image areas being wiped therefrom by the stationary wiping means I25 as the cylinder rotates and any remaining liquid upon the nonimage areas being removed by the rotary wiping means I2'I. In addition to removing the liquid from the non-image areas, the wiping means perform the further function of assisting in filling any small image areas which might normally not be filled with the liquid, especially when the latter is somewhat viscous. As the cylinder, now supplied with liquid in only the image areas and precharged by passage past the electrode means IIli, comes adjacent the web material, precharged by the electrode means I51, transfer of the precharged liquid to the precharged web material is effected by the electrostatic field of force between the electrodes 55 and 68. This transfer occurs whether or not the magnetic field provided by the electromagnets I0, II is utilized, the latter being employed simply for the purpose of confining the lines of force in the electrostatic field and thereby effecting a somewhat sharper image upon the web material.

If, instead of employing depressed image areas upon the surface of the cylinder 20, the surface be substantially uniform, a coating may be applied to web material M by slightly raising the sealing means 96, by removing the stationary wipers I25 and moving the wiping means I2! away from the surface of the cylinder 28. A uniform film of liquid will then be supplied to the cylinder which film will receive a precharge from the electrode means ma and this precharged liquid will be transferred to the precharged web material M by the transfer potential difference between the electrodes 55 and 68. When effecting coating it is normally unnecessary to employ the electromagnetic shielding means. In effecting coating in this manner, it is preferable to employ an imperforate shell of conductive material upon the cylinder at which shell is lightly etched or otherwise provided with a network of fine lines or grooves to facilitate distribution of the liquid over the surface thereof and to facilitate the formation of a uniform layer or coating on the web material. While the wiping means such as I25 and I2'I are normally removed from engagement with the cylinder 29 when producing a coating, as just described, wipers such as I2-5, but with their lower edges spaced from the cylinder 29 and/or adjustment of the wiping means I2'I adjacent to but spaced slightly from the surface of the cylinder 20, will remove excess liquid from the cylinder 20 but will leave a layer thereon which is subsequently transferred to the web material as a coating. This mode of operation is useful where the liquid is relatively viscous and tends to be unevenly distributed over the surface of the cylinder.

A second mode of employing the apparatus is to utilize a cylinder 2%) having perforate portions in the surface thereof corresponding to image areas and imperforate portions representing nonimage areas, the surface of the cylinder then being similar to that shown in Fig. 13. With such a cylinder in place and the apparatus otherwise constructed as shown in Fig. 1, liquid is sup-plied to the interior of the cylinder 20 through the bore or passageway 35 in the shaft 30 and exudes outwardly through the perforate areas, any liquid which may come upon the nonimage areas being removed by the wiping means which also serve to distribute the liquid into such image areas as, due to their small dimensions, are not perforate through the cylinder. The circuit for the several electrode means is the same as previously described for the firstrnentioned operation and hence the liquid receives a precharge by means of the electrode wires III of the electrode means III). The web material is electrically precharged by the electrode I57 and the liquid within the image areas is transferred by the electrostatic field of force extending between the electrodes 55 and 68 as the image areas pass therebetween due to rotation of the cylinder. As before mentioned, the magnetic field provided by the electromagnets III or II may be employed, if desired, this depending upon the characteristics of the web material and the image producing substance as well as upon the sharpness of the image desired.

If the cylinder 26 have its entire surface perforate and the wiping means I25 and I21 be removed from cooperative relationship with the cylinder, the apparatus being otherwise conditioned as just described, liquid supplied to the interior of the cylinder exudes from the entire surface thereof, is precharged and transferred to the precharged web material as a uniform coating, this transfer being effected by the electrostatic field between the electrodes 55 and 68. Likewise, as mentioned under Operation I above, wiping means such as I25 and [21 may be positioned adjacent the surface of the cylinder but spaced slightly therefrom to ensure a uniform layer of liquid on the surface of the cylinder when using the latter to coat with a liquid fed from within the cylinder.

III

In some instances, when ink orother liquid is supplied from within the cylinder 29, it is desirable to supply a second liquid such as a solvent to facilitate entry of the liquid such as the ink into small image areas which, due to their size do not have perforations thereunder, and hence have no means of direct supply of ink from the interior of the cylinder, this condition occurring especially when very fine image work is desired. In such an event, the apparatus is employed in substantially the same manner as previously described above under Operation II, except that the solvent or other second liquid is introduced through the conduit and applied to the exterior surface of the cylinder, while the ink or image forming substance proper exudes through the cylinder from the interior thereof. These two liquids, being compatible, mingle on the outer surface of the cylinder and hence the solvent thins the ink or other liquid coming from within the cylinder sufficiently to permit the latter to easily fill image areas which are imperforate but which are recessed or depressed below the larger non-image areas, this action being effected by the wipers as the cylinder is rotated therepast. The liquid upon the surface of the cylinder is precharged as is also the web material as previously described under Operation II and the transfer of the mingled substances to the web material is again effected by the electrostatic field of force between the electrodes 55 and 68.

Coating may likewise be effected by employing two compatible liquids supplied respectively from the interior and exterior of the cylinder 26 by removing the wipers !25 and the rotating wiping means I2? from cooperative relationship with the cylinder 20, and by slightly raising the sealing strip 95 carried by the member 83. In this case, the cylinder 28 has substantially its entire surface perforate so that a liquid supplied from the' interior thereof exudes throughout the periphery and mlngles with the second liquid introduced as a film upon the exterior surface. These mingled liquids are precharged and transferred to the prechargeol web material M in the same manner as previously described for coating under the second form of operation described above. Likewise, as mentioned above under Operation I and II, wiping means adjacent to but spaced from the surface of the cylinder may be used at times to facilitate forming a uniform thickness of mingled liquids on the surface of the cylinder prior to transfer to the web material.

Instead of employing the ink or other printing or coating substance from within the cylinder 20 and a solvent supplied to the exterior of the cylinder, the mode of supplying two liquids may be reversed so that the solvent is supplied from the interior of the cylinder and the ink suppli d directly to the exterior surface of the cylinder. The operations are otherwise the same as described above under III and either printing or coating may be performed in the same manner.

In employing smoke, vapor, gaseous suspensions, or the like, to form an image upon web material, the apparatus is conditioned substantially as shown in Fig. 2, from which it will be observed that the stationary wipers I have been removed, the rotatable wiping means I27 has been moved away from the cylinder 28, cylinder 22 has likewise been lowered so as to proide a greater space between it and the cylinder 20. The web material M is introduced into the apparatus by passing it around the guide rollers or cylinders I59, lSl, thence around the cylinder 20, and finally leading it from the machine substantially parallel with the incoming portion of the web. The sealing means 102 and 133 have the strips as thereof positioned in spaced relationship with respect to the cylinder sufficiently to permit free passage of the web material M therepast asare also the sealing strips 96 carried by the members 82 and The circult for the apparatus is then conditioned by throwing the switch I83 to dispose its blades in their broken line positions. The circuit for the apparatus is then such that the precharge electrode l$2 is now connected through the wire 2M, switch blade 203, wire 202, to and through the reversing switch it? to wire N6 of the precharge voltage supply. Likewise, the precharge electrodes I65 and I66 are connected through the switch blade 209 to the wire 205, through the switch blades 205* and H32, wire I88 to the reversing switch l8! and wire H5 connected to the other side of the precharge voltage supply. Therefore, the smoke due to its circulation through the compartments m8 and ill receives a precharge from the wires 65 and 33 while the web material M is precharged by passing near electrode H52. These precharges are of opposite polarities, which polarities may be selected in accordance with the type of materials utilized by proper positioning of the reversing switches S85, iEl. The electrodes 51 and 53 within the cylinder iii are now connected through the wire til, switch H35, wire 20!, switch blade I 55, wire I85 and switch I 8! to one side of the source of transfer voltage. The electrode means it? is connected by the wire 2538, switch blade lea, wires 93 and 13?, switch E55, wire I95, switch blade E32, and switch it] to wire H3 connected to the other side of the transfer voltage supply. Finally, the electrode means ilfl is connected through the wire to wire I97 and thence to the said other side of the voltage supply through the connections just described. l-Ience the electrode means it? and iii! are connects toget and together form the discharge electrode of the electrostatic field employed for transferring or depositing the precharged smoke or the like circulating through the compartments H8 and H9 upon the web material.

In employing the apparatus in this manner, the cylinder {it will have its surface substantially as shown in Fig. 14, that is to say, the image will be formed of conductive material whereas the non-image areas are formed of non-ccnductive or insulating material. smoke entering through the conduit t ll through the cor pertinent W3 intermediate the inner and outer thence through the open s l and the compartment Hii interthe inner wall at and the web material vi, smoke "eing withdrawn through the opening ill, and any smoke attempting to leak exteriorly of the housing past the member being withdrawn through the duct i 32 exte ding ad jacent the surface of the web material. Likewise, smoke may also be introduced through the conduit l i t and flows serially through the chem-- here or passages iii and lit, being renoved through the opening 123 and the conduit i125.

The precharged smoke circulating past the electrode means l6? and Ilii is transferred or dis posed upon the web material due to the action of the field of force between said st-mentioned electrodes and the electrode .ithin the cylinder. This field of force will be sequentially arranged in accordance with the image upon the cylinder 26 as successive conduct e portions of the surface of the latter, represen mg the image, move through the field of force. i-Ience, smoke or the like will be deposited upon the web material only in the areas thereof opposite image portions of the cylinder with the result that an image is formed thereon in accordance with that on the cylinder; see my above-mentioned copending application Ser. No. 74,822 for a more complete description of this mode of printing or coating and the broad claims thereto.

If it be desired to produce a coating upon web material by the use of smoke or fluid suspensions similar to smoke, this may be readily effected by substituting for the cylinder having an image surface, one having a conductive shell over the 23 entire periphery. The apparatus is otherwise the same as just described for image formation and is utilized in the same manner except that now the smoke or the like is deposited as a uniform layer or coating on the web material.

Yet another way of employing the apparatus is to utilize smoke, gaseous suspensions, or the like introduced through the conduits such as H31 and I I6 together with a liquid such as an adhesive or the like introduced through the interior of the cylinder 29 and exuding through the perforations therein. When employed in this manner, the apparatus will be conditioned substantially as shown in Fig. 1 with the cylinder having perforate image areas and imperforate non-image areas similar to that shown in Fig. 13. The web material M is led over the roller or cylinder I56 and over a portion of cylinder 22 to pass between the latter and the cylinder 20. The wipers I25 and the rotary wiping means I21 are in cooperative relationship with the cylinder 20, and at least in this instance, the stationary wipers I25 have opposite ends thereof staggered with respect to the end plates or walls 84, 85 of the housing, see Fig. 9. This provides a devious path for the smoke or the like coming into the inner compartments I II! and H9 through the openings I09 and I I8 thus permitting fiow of the smoke or the like while at the same time providing the necessary wiping action upon the surface of the cylinder.

The circuit for the several electrodes will be the same as described above for operations such as I, II, III, and IV. Hence the electrode means I51 provides a precharge upon the web material M and the electrode means I10 provides a precharge upon the mingled smoke and liquid upon the surface of the cylinder, it being understood that the liquid exuding through the perforations of the cylinder is compatible with the smoke and hence will pick up portions of the smoke circulating thereabout so that the smoke and liquid are mingled on the cylindrical surface. This mingled smoke and liquid are confined tothe image areas by action of the wiping means I25 and I21 which remove any mingled fluid and liquid from the non-image areas and hence the mingled fluid and liquid are transferred to the web material in the form of an image as the image portions of cylinder 20 and the web material pass through the electrostatic field existing between the electrodes 55 and 59, as before described. The polarities employed upon the several electrodes may be reversed, if necessary, depending upon the nature of the substances employed.

Coating may likewise be performed with mingled gas and liquid by employing the apparatus as just described except that the cylinder 29 has substantially the entire surface thereof perforate so that liquid exudes throughout the entire periphery and the wiping means are removed or spaced from the surface of the cylinder 29 sufficiently so that they permit a layer of mingled liquid and. fluid to be carried around to the electrostatic field as previously described.

VII

The apparatus disclosed may be employed for forming an image or coating upon web material by means of smoke, gaseous suspensions, or the like, exuding through openings in the surface of the cylinder. For a. printing operation in this manner the cylinder 29 will be formed substantially as shown in Fig. 13 with perforate image areas and imperforate non-image areas. The apparatus will be conditioned substantially as shown in Fig. 2 and as described above with respect to Operation V. That is, the wipers I25 are removed, the wiping means I21 is positioned out of engagement with respect to the cylinder 20, and the cylinder 22 is lowered slightly with respect to the cylinder 20. The web material M is brought into the apparatus over the rollers or cylinders I69, IM and is passed around the periphery of the cylinder within the housing, as shown in Fig. 2.

The circuit is prepared by moving the switch I83 to dispose the blades thereof in their broken line positions, the switch blades 203, 205 are disposed in their broken line positions and the switch I96 is simultaneously actuated to reverse the connections therethrough. In addition, the switch blade 299 is moved to its broken line position. Therefore, a circuit is completed for energization of the electrode means I52 through the wire 204, switch blade 293, wires 201 and I88, and the reversing switch I81 to the wire I15 connected to one terminal of the precharge voltage supply. A precharge for the smoke, or the like, which now flows into the interior of the cylinder through the bore 35 of the shaft 39, is provided by charging the inner shell 43 of the cylinder 29. This is effected through the contact 63 which rides upon the said inner shell and is now connected by the wire 65, switch blade 209, wire 296, switch blade 2B5, wires 298 and I92, and the reversing switch M1 to the Wire I16 connected with the other terminal of the precharge voltage supply. The electrode means I61 is connected through the wire 299 and switch blade I99 to the wires I98 and I 91, thence through the reversing switch I96, wire ZIII, switch blade I86, wire I85, and reversing switch IN to wire I1 3 connected to one of the terminals of the transfer voltage supply. Likewise, the electrode means I10 is connected to the same terminal of the transfer voltage supply by means of wires I9I, I91, switch I96, etc. The electrode means 51 and 58 are connected to the other terminal of the source of transfer voltage through the wire 59, switch I96, wire I95, switch blade I82, reversing switch I 8| and wire I13. Consequently, the electrodes I51, I10 form the attraction electrodes for eifecting transfer of the smoke to the web material, while the electrodes 51, 58 form the discharge electrodes for this purpose, it being observed that the polarities applied to the smoke and web material are in the proper relationship for cooperation with the electrostatic field since the precharge upon the web material is now applied on the opposite side thereof from that on which the image is formed rather than on the same side, as in the prior operations.

In operating in accordance with this procedure, smoke, or the like, introduced into the interior of the cylinder is precharged as it passes the inner shell 43 and this smoke exudes through the perforate areas of the cylinder, being transferred to and deposited upon the precharged web material, Wrapped around the cylinder 29, under the influence of the electrostatic field of force between the electrode means such as I51, 51 and I19, 58. Any smoke which might tend to exude through the uncovered portion of the cylinder and thereby escape from the housing is substantially blocked by the shield 11a.

Coating may be eifected in accordance with the operation just described by simply omitting the imperforate covering or portions of the cylinder 20 so that substantially the entire surface area of the cylinder is perforate, the apparatus being otherwise constructed and operating in the manner just described. In addition to employing smoke in this manner, coatings may also be formed by employing a liquid or liquids or liquid vapor mixed with smoke or the like.

VIII

The apparatus may likewise be employed for forming either an image or coating upon web material by employing smoke supplied from the interior of the cylinder and a liquid compatible therewith, such as an adhesive supplied to the cylinder 20 from the outside thereof. The apparatus employed in this manner is set up in the manner described above with respect to Fig. 1 and Operation III. The operation is substantially the same as that described under III above except that it is now smoke rather than ink or the like which exudes from the perforate portions of the cylinder 20 and mingles with the liquid, which in this case may be an adhesive, supplied to the surface of the cylinder from between the mer. bars 82 and 83. The mingled fluid, such as smoke and liquid, are transferred to the web material M by the electrostatic field between the electrodes 55 and 68, precharges being supplied to the mingled liquid and smoke by the electrode means I and to the web material M by the electrode means 157. Since the operation is otherwise the same as described above under III, a detailed description thereof need not be repeated.

The apparatus may likewise be utilized for forming an image or coating by using smoke, or other gaseous suspensions, by introducing the latter through the conduits such as IE7, H6 as previously described under Operation V above. In the instant case, however, a suitable compatible liquid such as an adhesive is vaporized or atomized and mixed with the smoke to provide a composite coating or image formation upon the web material. The apparatus is conditioned for employment, however, the same as described above under V and hence the description need not be repeated.

OTHER OPERATIONS Other methods of using the disclosed apparatus will readily appear to those skilled in the art to which it pertains after a study of the above description and the accompanying drawings. Without attempting to exhaust all such possibilities, it may be further noted that, in addition to the above, coating may be effected by employing smoke or liquid in vapor form. supplied to only the left side of the housing, as viewed in Fig. 2, through the conduit 1 ii! with a compatible liquid such as a solvent or adhesive in liquid form introduced through the conduit 95. In this operation the web material M will be led into the apparatus and about the periphery of the cylinder 20, the cylinder having a conductive material over its entire surface. The electrode means I62 will be connected for precharging the web material and the electrode means 165 is connected to precharge the smoke or vaporized liquid. The electrode means I61 and 57 will be connected to the source of transfer voltage so that the smoke or vaporized liquid circulating through the left side of the housing, as viewed in Fig. 2, is transferred to the web material by the electrostatic field between the electrode means l6! and 51, the operation in this respect being similar to that described with respect to Operation V. The liquid enters the apparatus, as mentioned before, through the conduit and is supplied 11 l 3 the members 82 and as a thin c; y by adjusting the sealing means or member carried by the vertical plate member slightly upward- 1y out of contact with the cylind r This liquid will then be disposed as a co lg or layer on top of the web material M and superimposed upon the vaporized liquid which was transferred to the web material and imbedded therein during the passage through the electrostatic field existing between the electrode means i 6'! and 57. The said liquid layer may be firmly united with the web material and the previously applied vaporized liquid by the action of the electrostatic field present between the electrode means no and 58 and through which the web material with the coating substances thereon pass.

A coating of a liquid may also be applied to web material such as M passing about the cylinder 2%} by employing the apparatus as described above, and as shown in Fig. 2, except that neither smoke nor vaporized liquid is introduced through the conduit iii. In such a situation liquid is simply supplied through the conduit 25 and the layer or coating thus applied to the web material as it passes around the cylinder is firmly united or driven into the said material by the electrostatic field of force between the electrodes lit and 53.

In addition to the above modes of operation of the apparatus and methods which may be effected by using the same, others may be devised by those skilled in the art. Likewise, the apparatus as shown and described may have portions thereof varied and other conventional devices may be added thereto to facilitate the operations. As an example of the latter, static eliminators of conventional type may be provided for cooperation with the web material such as M and M before the latter is conducted past the precharge electrodes such as i5"! and 552 and/or after the material emerges from the apparatus. Also, heating and/or drying devices may be employed for cooperation with the web material either prior to passage of the latter through the apparatus, subsequent to such passage, or both. For example, static eliminators and heating or drying means may be employed in conjunction with the web material in a manner similar to that indicated in my copending application Ser. No. 74,822 filed February 5, 1949. See also Huebner Patent 2,445,271 issued on July 13, 1948, which illustrates static eliminating means for cooperation with web material in electronographic printing or coating processes.

In view of these and other modifications that may be effected in the apparatus and procedure disclosed, it will be understood that the invention is not to be considered as limited to the exact details of procedure and apparatus described and shown, but that these illustrations and descriptions are only representative of practical embodiments of the invention.

Having thus described th invention, I claim:

1. The method of producing a deposit on a material which comprises providing a perforate body, supplying a first fluid to one side of said body in a manner such that the said fiuid exudes to the other side of said body, supplying a second fluid compatible with the first fluid to the said other side of said body so that the fluids mingle on the said other side, bringing the material adjacent the said other side of the body, and establishing an electrostatic field of force extending through the said body and the material on which the deposit is to be formed whereby the said mingled fluids are simultaneously transferred to the said material by the said field of force.

2. The method of produding a deposit on web material which comprises providing a hollow rotatable cylinder having a perforate periphery, supplying a first fluid to the interior of said cylinder in a manner causing the said fluid to exude through the periphery thereof, supplying a second fluid compatible with the first fluid directly to the exterior periphery of said cylinder so that the said fluids mingle on the surface of the cylinder, providing an electrostatic field of force extending through a portion of the side wall of said cylinder, and moving web material through said field of force and adjacent the surface of said cylinder while rotating the latter whereby the said mingled fluids are simultaneously deposited upon the web material by the said field of force.

3. The method of producing an image on a material which comprises providing a body having perforate areas corresponding with image areas of the image to be produced and imperforate areas corresponding with non-image areas, supplying a first fluid to one side of said body in a manner such that the fluid exudes through the said perforate areas, supplying a second fluid compatible with the first fluid directly to the said other side of said body, wiping the non-image areas to remove the said second fluid therefrom and confine the said second fluid to the image areas whereby the said fluids are mingled in said image areas, and establishing an electrostatic field of force extending through said body and the material on which the image is to be produced whereby the said mingled fluids are deposited upon said material in the form of an image corresponding with that upon the said body.

4. The method of producing an image on web material which comprises providing a hollow rotatable cylinder the periphery of which comprises imperforate portions corresponding with nonimage areas and perforate portions corresponding with image areas of the image to be produced, supplying a first fluid to the interior of said cylinder in a manner such that the said fluid exudes through the said perforate portions, supplying a second fluid compatible with the first fluid directly to the exterior periphery of said cylinder, wiping the non-image portions of said cylinder to remove the said second fluid therefrom and confine said second fluid to the image portions whereby the said fluids are mingled in said image portions, providing an electrostatic field of force extending through a portion of the periphery of said cylinder and moving web material through said field of force and adjacent the surface of said cylinder while rotating the cylinder whereby the said mingled fluids are deposited upon said web material in the form of an image corresponding with that upon the cylinder.

"5. An apparatus of the character described comprising a rotatable cylinder having recesses in the surface thereof representative of image areas to be produced on web material, a stationary housing surrounding a portion of the periphery of said cylinder, means in said housing adapted to supply a liquid to the surface of said cylinder, means in said housing extending axially adjacent the surface of said cylinder and cooperating with the liquid supply means to regulate the quantit of liquid supplied to the cylinder, wiper means in said housing extending axially of said cylinder in cooperative relationship with the curved surface of said cylinder to remove at least a part of the liquid from the nonimage areas, rotatable wiping means adapted to cooperate with the periphery of said cylinder to remove liquid from the non-image areas, means for guiding web material adjacent the surface of said cylinder exteriorly of said housing, means cooperating with said web material to provide an electrical precharge thereon prior to passage of said web material past said cylinder, and means for creating an electrostatic field of force extending through the said web material, the last-mentioned means including first electrode means within said cylinder and a second electrode means externally of said cylinder and spaced from the surface thereof, whereby the liquid on the said image areas of the cylinder is transferred to said material by the said electrostatic field of force.

6. An apparatus of the type defined in claim 5 and further comprising electrode means Within said housing adjacent the surface of said cylinder to impart an electrical precharge to the liquid on the said cylinder.

'7. An apparatus of the type defined in claim 5 wherein the said rotatable wiping means comprises a cylindrical wiping surface rotatable about an axis extending parallel with the axis of said cylinder, and means to move the axis of said wiper towards or away from the axis of said cylinder.

8. An apparatus of the character described comprising a rotatable cylinder, a stationary housing surrounding a portion of the periphery of said cylinder, means in said housing adapted to supply a liquid to the surface of said cylinder, rotatable wiping means adapted to cooperate with the periphery of said cylinder and reimove excess liquid therefrom, a housing substantially surrounding said wiping means and having a longitudinally extending opening adjacent said cylinder through which a portion of said wiping means is adapted to extend into engagement with said cylinder, fluid pressure means cooperating with said wiping means to remove therefrom liquid which is wiped from said cylinder, means for guiding web material adjacent the surface of said cylinder exteriorly of the first-mentioned housing, and means for creating an electrostatic field of force extending through the said web material including a first electrode means within said cylinder and a second electrode means externally of said cylinder and spaced from the surface thereof, whereby the liquid remaining on said cylinder surface is tranferred to said material by the said electrostatic field of force.

9. An apparatus of the type defined in claim 8 wherein the said Wiping means comprises a cylindrical wiping member mounted to rotate about an axis extending parallel with the axis of said cylinder, and the said fluid pressure means for removing liquid from said wiping means includes means to apply fluid pressure longitudinally of the said wiping member from the interior thereof.

10. An apparatus of the type defined in claim 8 wherein the said wiping means comprises a hollow cylindrical member having a permeable wiping surface rotatable about an axis extending parallel with the axis of said cylinder, and 

